Many machines require replenishment or replacement of consumable supplies. Printers require ink or toner and paper. Removable media drives, such as DVD-R drives, require media for use. Automobiles require fuel and oil. Coffemakers require coffee, just as breadmakers require flour. The lifetime cost of a machine reflects not just the cost to build the machine, but the cost of consumable supplies (consumables) needed to operate the machine over its lifetime.
Consumers are often more influenced by initial purchase price than by lifetime cost of goods. As a result, many machines are sold at, or even below, cost; the machine manufacturer hoping to make up the deficit and turn a profit from later sales of the consumables required to keep the machine running.
Freeloading manufacturers may recognize that the profit is in consumables, and undercut the machine manufacturer's price for them; if consumers buy from freeloaders, the machine manufacturer must raise prices on machines to stay in business. If a customer agrees to buy consumables from a machine manufacturer, in return for a low initial purchase price, it is desirable to enforce the contract automatically.
Some manufacturers produce and sell goods at a low price for use in one country, while selling the same or similar goods at a higher price for use in another country. A grey market often exists whereby merchants buy the goods in low-priced countries and resell them in high-priced countries. It can be desirable to restrain the grey market.
Some machines must be adjusted for optimum performance with different lots, or manufacturers, of consumables. For example, consider color printers. If a batch of ink cartridges has a more intense magenta ink than prior cartridges, photographs printed using those ink cartridges will have unrealistic color unless the printer is adjusted to compensate for the over-intense magenta ink by slightly reducing the amount of magenta ink applied to pixels of the photographs. A slight reduction in magenta ink can be achieved by slightly shortening inkjet pulsewidths, however this can only happen automatically if lot-dependent ink density information is conveyed to the printer.
Prior Taggants
Small amounts of identifiable materials, known as taggants, can be added to commodities to allow those commodities to be identified. These taggants can be used to identify a manufacturer, a lot, or a type of a commodity.
U.S. Pat. No. 6,501,825, “Methods for identification and verification”, describes use of x-ray fluorescent taggants to label substances; its background section describes addition of ultraviolet and infrared fluorescent taggants to substances for identification.
U.S. Pat. No. 6,610,351 describes use of Raman scattering to measure particle sizes of particulate taggants.
Serial Numbers
Many items, from automobiles through drugs to printer ink cartridges and currency, have serial and/or lot numbers attached. For purposes of this document, the term serial number includes lot numbers.
Serial numbers often encode information beyond sequence of manufacture. For example, a typical automobile VIN number encodes vehicle model, model year, engine size, and place of manufacture in addition to production sequence. Drug lot numbers may encode drug type and expiration date as well as place and sequence of manufacture. DVD disk player serial numbers may encode information regarding regions of the world in which the player is to be sold, and which DVD disks the player is permitted to play. Software serial numbers often incorporate encrypted enabling information for a program.
It can therefore be desirable to restrict use of perishable goods, such as drug ingredients, to use with their original cartridges such that expiration dates can be enforced. It can be desirable to detect counterfeit consumables, or consumables manufactured for use elsewhere in the world. It can also be desirable to lock particular lots of consumables to use on particular models and types of machines.